From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Subject: Re: [PATCH v3 04/13] nEPT: Define EPT-specific link_shadow_page()
Date: Tue, 21 May 2013 16:15:05 +0800
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References: <1368939152-11406-1-git-send-email-jun.nakajima@intel.com> <1368939152-11406-4-git-send-email-jun.nakajima@intel.com>
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Cc: kvm@vger.kernel.org, Gleb Natapov <gleb@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>
To: Jun Nakajima <jun.nakajima@intel.com>
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On 05/19/2013 12:52 PM, Jun Nakajima wrote:
> From: Nadav Har'El <nyh@il.ibm.com>
> 
> Since link_shadow_page() is used by a routine in mmu.c, add an
> EPT-specific link_shadow_page() in paging_tmp.h, rather than moving
> it.
> 
> Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
> Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
> Signed-off-by: Xinhao Xu <xinhao.xu@intel.com>
> ---
>  arch/x86/kvm/paging_tmpl.h | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
> index 4c45654..dc495f9 100644
> --- a/arch/x86/kvm/paging_tmpl.h
> +++ b/arch/x86/kvm/paging_tmpl.h
> @@ -461,6 +461,18 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
>  	}
>  }
> 
> +#if PTTYPE == PTTYPE_EPT
> +static void FNAME(link_shadow_page)(u64 *sptep, struct kvm_mmu_page *sp)
> +{
> +	u64 spte;
> +
> +	spte = __pa(sp->spt) | VMX_EPT_READABLE_MASK | VMX_EPT_WRITABLE_MASK |
> +		VMX_EPT_EXECUTABLE_MASK;
> +
> +	mmu_spte_set(sptep, spte);
> +}
> +#endif

The only difference between this function and the current link_shadow_page()
is shadow_accessed_mask. Can we add a parameter to eliminate this difference,
some like:

static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp, bool accessed)
{
	u64 spte;

	spte = __pa(sp->spt) | PT_PRESENT_MASK | PT_WRITABLE_MASK |
	       shadow_user_mask | shadow_x_mask;
	
	if (accessed)
		spte |= shadow_accessed_mask;

	mmu_spte_set(sptep, spte);
}

?